US 9,923,154 B2 · Assignee: KONICA MINOLTA, INC. · Inventors: Oshiyama; Tomohiro et al.
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An object of the present invention is to provide an organic electroluminescent element that has low drive voltage, high emission efficiency, long endurance and an excellent effect of preventing generation of dark spots. Another object of the present invention is to provide a lighting device and a display device each including the organic electroluminescent element. The organic electroluminescent element according to the present invention includes an anode, a cathode, and an emissive layer, and the organic electroluminescent element includes a layer containing compound A that has a difference of 0 nm or more and 5 nm or less between the maximum emission wavelength on the shortest wavelength side in an emission spectrum measured at 300 K and the maximum emission wavelength on the shortest wavelength side in an emission spectrum measured at 77 K.
Electroluminescent displays (ELDs) have already been used in emissive electronic display devices. One of components of an ELD is an inorganic electroluminescent element or an organic electroluminescent element (hereinafter, referred to as an organic EL element). The inorganic electroluminescent element has been used as a planar light source. Such an emissive element, however, requires high voltage of alternating driving current. The organic EL element has a structure of an emissive layer containing an emissive compound interposed between a cathode and an anode. Electrons and holes are injected, into the emissive layer and are recombined to form excitons. When, this exciton is deactivated, emission of light (fluorescence or phosphorescence) occurs. This organic EL element can emit light by such a phenomenon at a voltage of several to several tens of volts. Moreover, the organic EL element
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This application is a 371 of PCT/JP2012/053077 filed on Feb. 10, 2012, which claims the priority of Japanese Patent Application No. 2011-030626 filed on Feb. 16, 2011, the contents of each of which are incorporated herein by reference.
The invention relates to an organic electroluminescent element, a lighting device and a display device, and more particularly to an organic electroluminescent element and a compound suitable for use in the organic electroluminescent element.
Electroluminescent displays (ELDs) have already been used in emissive electronic display devices. One of components of an ELD is an inorganic electroluminescent element or an organic electroluminescent element (hereinafter, referred to as an organic EL element). The inorganic electroluminescent element has been used as a planar light source. Such an emissive element, however, requires high voltage of alternating driving current.
The organic EL element has a structure of an emissive layer containing an emissive compound interposed between a cathode and an anode. Electrons and holes are injected, into the emissive layer and are recombined to form excitons. When, this exciton is deactivated, emission of light (fluorescence or phosphorescence) occurs. This organic EL element can emit light by such a phenomenon at a voltage of several to several tens of volts. Moreover, the organic EL element has a wide viewing angle and a high visibility because it is a self-luminescent element. Furthermore, the organic EL element, which is a thin-film type of full solid-state element, is attracting attention from the points of view of space saving and of portability.
An example development of the organic EL elements for practical use is an organic EL element utilizing phosphorescent emission from an excited triplet state reported by Princeton University (M. A. Baldo et al., nature, Vol. 395, pp. 151-154, 1998). As described in U.S. Pat. No. 6,097,147 and M. A. Baldo et al., nature, Vol. 403, No. 17, pp. 750-753 (2000), research on materials to generate phosphorescence at room temperature has been carried out more actively since then.
Moreover, a recently discovered organic EL element utilizing phosphorescent emission can achieve emission efficiency, in principle, about four times higher than those of previous elements utilizing fluorescent emission. Research and development works on the layer structure of emissive elements and electrodes are being carried out worldwide as well as development work on materials for the recently discovered organic EL element.
For example, many compounds have been synthesized and examined mainly for heavy metal complexes such as a series of iridium complexes, and have been used for an emissive layer in an organic electroluminescent element (also called as an organic EL element) as described in S. Lamansky et al., J. Am. Chem. Soc., Vol. 123, p. 4304 (2001), for example.
Although an organic EL device utilizing phosphorescent emission is a system of great potential, major technical issues for the device are the way of controlling the position of the emissive center, particularly stable recombination inside the emissive layer and stable emission of light, as well as enhancement of the emissive property of a phosphorescent compound itself, from the viewpoints of efficiency and lifetime of the element.
In order to enhance the emissive property of a phosphorescent compound, there are two possible approaches:
increasing the radiative rate constant (kr) and
decreasing the non-radiative rate constant (knr), when the lowest excited triplet state (T1) is deactivated to the ground state (S0).
A possible specific means for decreasing the non-radiative rate constant (knr) is to sterically control the structure of a ligand of the phosphorescent compound to decrease structural changes between the ground state and the excited state.
With regard, to the iridium complex, which is a typical phosphorescent compound, examples in which the steric structure is controlled by a combinated ligand of dibenzofuran and pyridine are described in, for example, Japanese Patent Application Laid-Open Publication Nos. 2002-332291, 2005-23071 and 2002-23072.
Similar applications are described for iridium complexes formed with phenylpyrazole derivatives (see Patent Literatures 1 and 5), phenylimidazole derivatives (see Patent Literatures 2 and 3), and derivatives containing a carbene moiety as a ligand (see Patent Literature 4 and Non Patent Literature 1).
A platinum complex including a ligand having π (pai)-conjugation extending over the benzene ring of the ligand is synthesized (Non Patent Literature 2).
These complexes are, however, not satisfactory in terms of providing an organic EL element that has nigh emission efficiency and low drive voltage, excels in heat endurance and raw storability, and has a long lifetime. A further solution is therefore being sought. CITATION LIST Patent Literature (PTL)
PTL 1: International Publication No. WO2004/085450 PTL 2: International Publication No. WO2009/060757 PTL 3: Japanese Patent Application Laid-Open Publication No. 2010-135467 PTL 4: International Publication No. WO2009/003898 PTL 5: Japanese Patent Application Laid-Open Publication No. 2010-254642 Non Patent Literature (NPL)
NPL 1: Hisahiro Sasabe et al., Advanced Materials, Vol. 22, pp. 5003-5007
NPL 2: Yoshiaki Sakurai et al., The 71th Academic Lecture; The Japan Society of Applied Physics (Autumn 2010, Nagasaki University, 17p-ZK-5) SUMMARY OF INVENTION Technical Problem
An object of the present invention is to provide an organic electroluminescent element that has low drive voltage, high emission efficiency, high durability and an excellent effect of preventing dark spots from forming. Another object of the present invention is to provide a lighting device and a display device each including the organic electroluminescent element. Means to Solve the Problem
The objects described above of the present invention can be achieved by means (aspects) described below.
1. An organic electroluminescent element including an anode, a cathode, and an emissive layer, and the organic electroluminescent element includes a layer containing compound A. The compound A has a difference, between a maximum emission wavelength on a shortest wavelength side in an emission spectrum measured at 300 K and a maximum emission wavelength on a shortest wavelength side in an emission spectrum measured at 77 K, of 0 nm or more and 5 nm or less.
2. The organic electroluminescent element of an aspect 1, in which the layer containing the compound A is the emissive layer.
3. The organic electroluminescent element of an aspect 1 or 2, in which the compound A is a phosphorescent compound.
4. The organic electroluminescent element of any one of aspects 1 to 3, in which the compound A is a compound represented by Formula (1):
##STR00001## (where, C.sub.10 and C.sub.11 each represent a carbon atom; A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa; Ra represents a hydrogen atom or a substituent; P.sub.1 represents an oxygen atom, a nitrogen atom, or a sulfur atom; P.sub.2, P.sub.3 and P.sub.4 each represent CRb, C(RcRd), a nitrogen atom, NRe, Si(RfRg), an oxygen atom or a sulfur atom; Rb, Rc, Rd, Re, Rf and Rg each represent a hydrogen atom or a substituent; Rb, Rc, Rd and Re do not form any ring by mutual bounding.
A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group; k represents 0 or an integer of 1; B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom, and these five atoms forms a five-membered aromatic nitrogen-containing heterocyclic ring; R.sub.0 represents a hydrogen atom or a substituent; X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand; X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or on oxygen atom; the bonds between C.sub.11 and P.sub.4, C.sub.11 and P.sub.3, P.sub.4 and P.sub.3, P.sub.3 and P.sub.2, P.sub.2 and P.sub.1, and P.sub.1 and C.sub.10 are each a single bond or double bond; L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; n represents an integer of 1 to 3; m represents an integer of (3-n); and M represents a transition metal element in Groups VIII to X of a periodic table.)
5. The organic electroluminescent element of an aspect 4, in which the compound represented by the Formula
is a compound represented by Formula (2):
##STR00002## (where, A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa.
Ra represents a hydrogen atom or a substituent.
D.sub.1, D.sub.2 and D.sub.3 each represent CRb or a nitrogen atom.
Rb represents a hydrogen atom or a substituent; Rbs do not form any ring by mutual bounding.
A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group; B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided, that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom; R.sub.0 represents a hydrogen atom or a substituent.
X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand; X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom; L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; n represents an integer of 1 to 3; m represents an integer of (3-n); and M represents a transition metal element, in Groups VIII to X of the periodic table.)
6. The organic electroluminescent element of an aspect 4, in which the compound represented by the Formula
is a compound represented by Formula (3):
##STR00003## (where, A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa.
Ra represents a hydrogen atom or a substituent.
R.sub.61, R.sub.62 and R.sub.63 each represent a hydrogen atom or a substituent; A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group; R.sub.61, R.sub.62 and R.sub.63 do not form any ring by mutual bounding.
B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom; R.sub.0 represents a hydrogen atom or a substituent.
X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand; X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom; L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; n represents an integer of 1 to 3; m represents an integer of (3-n); and M represents a transition metal element in Groups VIII to X of the periodic table.)
7. The organic electroluminescent element of an aspect 4, in which the compound represented by the Formula
is a compound represented by Formula (4):
##STR00004## (where, A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa.
Ra represents a hydrogen atom or a substituent.
Z.sub.0 represents an oxygen atom or a sulfur atom.
Z.sub.1, Z.sub.2 and Z.sub.3 each represent C(RcRd), NRe, Si(RfRg), an oxygen atom or a sulfur atom.
Rc, Rd, Re, Rf and Rg each represent a hydrogen atom or a substituent; Rc, Rd and Re do not form airy ring by mutual bounding.
A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.
B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom; R.sub.0 represents a hydrogen atom or a substituent.
X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand; X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom.
L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; n represents an integer of 1 to 3; m represents an integer of (3-n).
M represents a transition metal element in Groups VIII to X of the periodic table.)
8. The organic electroluminescent element of an aspect 4, in which the compound represented by the Formula
is a compound, represented by Formula (5):
##STR00005## (where, A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa; Ra represents a hydrogen atom or a substituent.
Y.sub.1 represents an oxygen atom, a sulfur atom, C(RcRd), NRe or Si(RfRg).
Rc, Rd, Re, Rf and Rg each represent a hydrogen atom or a substituent.
R.sub.71 represents a hydrogen atom or a substituent; R.sub.71, Rc and Rd do not form any ring by mutual bounding.
A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.
B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom; R.sub.0 represents a hydrogen atom or a substituent.
X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand; X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom.
L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; n represents an integer of 1 to 3; m represents an integer of (3-n).
M represents a transition metal element in Groups VIII to X of the periodic table.)
9. The organic electroluminescent element of an aspect 4, in which the compound represented by the Formula
is a compound represented by Formula (6):
##STR00006## (where, A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa.
Ra represents a hydrogen atom or a substituent.
Y.sub.2 represents a nitrogen atom or CRb.
Rb represents a hydrogen atom or a substituent.
Y.sub.3 represents an oxygen atom or a sulfur atom.
R.sub.81 represents a hydrogen atom or a substituent; R.sub.81 and Rb do not form any ring by mutual bounding.
A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.
B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom; R.sub.0 represents a hydrogen atom or a substituent.
X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand; X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom.
L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; n represents an integer of 1 to 3; m represents an integer of (3-n).
M represents a transition metal element in Groups VIII to X of the periodic table.)
10. The organic electroluminescent element of an aspect 4, in which the compound represented by the Formula
is a compound represented by Formula (7):
##STR00007## (where, A.sub.1 and A.sub.2 each represent a nitrogen atom, or CRa.
Ra represents a hydrogen atom or a substituent; Y.sub.4 represents an oxygen atom or a sulfur atom.
Y.sub.5 and Y.sub.6 each represent C(RcRd), NRe, Si(RfRg), an oxygen, atom or a sulfur atom.
Rc, Rd, Re, Rf and Rg each represent a hydrogen atom or a substituent; Rc, Rd and Re do not form any ring by mutual bounding.
A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.
B.sub.1 to B.sub.5 each represent, a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom; R.sub.0 represents a hydrogen atom or a substituent.
X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand; X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom; L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; n represents an integer of 1 to 3; m represents an integer of (3-n); and M represents a transition metal element in Groups VIII to X of the periodic table.)
11. The organic electroluminescent element of any one of aspects 4 to 10, in which the ring formed by B.sub.1 to B.sub.5 is an imidazole ring or a pyrazole ring.
12. The organic electroluminescent element of any one of aspects 1 to 11, in which the emissive layer is a layer formed by using a coating liquid containing the compound A.
13. The organic electroluminescent element of any one of aspects 1 to 12, in which the emissive layer emits white light.
14. A lighting device including the organic electroluminescent element of any one of aspects 1 to 13.
15. A display device including the organic electroluminescent element of any one of aspects 1 to 13. Advantageous Effects of Invention
These means or aspects according to the present invention described above can provide an organic electroluminescent element that has low drive voltage, high emission efficiency, high durability and an excellent effect of preventing dark spots from forming. Also, they can provide a lighting device and a display device each including the organic electroluminescent element.
FIG. 1 is a schematic view showing an exemplary display device including an organic EL element.
FIG. 2 is a schematic view of a display portion A.
FIG. 3 is a schematic view of a pixel.
FIG. 4 is a schematic view of a full color passive-matrix display device.
FIG. 5 is a diagrammatic illustration of a lighting device.
FIG. 6 is a schematic view of a lighting device.
An organic electroluminescent element (hereinafter, referred to as an organic EL element) according to the present invention includes an anode, a cathode, and an emissive layer. The organic electroluminescent element includes a layer containing a compound A, the compound A is characterized in that a difference between the maximum emission wavelength on the shortest wavelength side in an emission spectrum measured at 300 K and the maximum emission wavelength on the shortest wavelength side in an emission spectrum measured at 77 K is 0 nm or more and 5 nm or less.
According to the present invention, the layer containing the compound A can provide an organic EL element that has low drive voltage, nigh emission efficiency, long endurance and an excellent effect of preventing dark spots from forming.
The reason why the compound A according to the present invention, brings about the above advantageous effects of the present invention is not clear, but may be presumed as follows.
As to one of disadvantages with conventional metal complexes, the inventors have assumed that significant change in the molecular structure of a phosphorescent compound between the ground state (S0) and the excited triplet state (T1) at the time of emission of light induces increased non-radiative deactivation, resulting in failure for obtaining an organic EL element having long lifetime of the element and high emission efficiency to ensure practical use, and thus the inventors have diligently studied the disadvantageous phenomenon.
As a result, the present inventors have found that incorporation of a metal complex, which was a compound A, has improved lifetime of the element and increased emission efficiency.
It has been found that a phosphorescent compound represented by a metal complex has often a ligand composed of two different rings, and if an aromatic hydrocarbon ring group or an aromatic heterocyclic group is attached as a substituent to a ring of the ligand (for example, A.sub.0 as a substituent on the Ring B in the drawing below), then an angle of rotation (φ1) at the junction of the ring and the substituent becomes the largest structural change portion between S0 and T1. It has also been found that this structural change is reflected in a difference in the 0-0 transition band between the emission spectra measured at 77 K and 300 K.
An appropriate sterically bulky substituent on the other ring (for example, P.sub.1 as a substituent on the Ring A in the drawing below) inhibits changes in the angle of rotation associated with excitation, resulting in a rigid molecular structure and decreasing of the value of knr. This is assumed to bring about the advantageous effects of the present invention.
However, too bulky P.sub.1 leads to larger φ2. This makes it difficult to form a complex, and even if formed, the resulting complex is unstable.
It has been found that when a substituent P.sub.1 forms a ring (the dotted line connecting the Ring A with P.sub.1 in the drawing below) enhances its effect. It is presumed that an organic EL element using a compound having a difference of 0 nm or more and 5 nm or less in the 0-0 transition band between the emission spectra measured at 77 K and 300 K has a very small, structural change between S0 and T1, and can exhibit the advantageous effects of the present invention. It is presumed that a compound having a difference above 5 nm has a higher knr along with a larger structural change, leading to a decrease in efficiency and stability.
The compound A has a difference of 0 nm or more and 5 nm or less between the maximum, emission wavelength on the shortest, wavelength side in a emission spectrum measured at 300 K and the maximum, emission wavelength on the shortest wavelength side in a emission spectrum measured, at 77 K.
The maximum emission wavelength as used herein corresponds to a peat wavelength in the emission band assigned to the 0-0 transition (also known as the 0-0 transition band) in an emission spectrum. The 0-0 transition band is a maximum emission wavelength that appears on the shortest wavelength side in an emission spectrum chart, and determined by the following measurement method.
(Measurement Method of 0-0 Transition Band in Emission Spectrum)
A compound to be measured is dissolved in 2-methyltetrahydrofuran that is thoroughly deoxygenated by nitrogen bubbling or the like, and the solution is loaded into a measuring cell, followed by irradiation with excitation light at a liquid nitrogen temperature of 77 K so as to measure an emission spectrum after irradiation of the excitation light.
For any compound that cannot dissolve in such a solvent, any other solvents may be used to dissolve it (substantially, the solvent effect on the emission wavelength is negligibly slight in the measurement method).
The determination of the 0-0 transition band will be described. The 0-0 transition band in the present invention is defined by a maximum emission wavelength that appears on the shortest wavelength side in the phosphorescence spectrum obtained by the measurement described above.
The emission spectrum of the solution prepared above is similarly measured at 300 K to determine another 0-0 transition band. The difference between the 0-0 transition bands at 300 K and 77 K is then calculated.
Typical examples of the compound A having such a difference between the 0-0 transition bands include compounds represented by Formula (1).
(Compounds Represented by Formula (1))
The compounds represented by Formula
will now be described.
In Formula (1), C.sub.10 and C.sub.11 each represent a carbon atom; A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa; Ra represents a hydrogen atom or a substituent; P.sub.1 represents an oxygen atom, a nitrogen atom, or a sulfur atom; P.sub.2, P.sub.3 and P.sub.4 each represent CRb, C(RcRd), a nitrogen atom, NRe, Si(RfRg), an oxygen atom or a sulfur atom; and Rb, Rc, Rd, Re, Rf and Rg each represent a hydrogen atom or a substituent.
In Formula (1), Rb, Rc, Rd, and Re do not form any ring by mutual bounding, A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group; k represents 0 or an integer of 1; B.sub.1 to B.sub.5 each represent, a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom, and these five atoms form, a five-membered aromatic nitrogen-containing heterocyclic ring. R.sub.0 represents a hydrogen atom or a substituent. X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand, and X.sub.1 and X.sub.2 each independently represents a carbon atom, a nitrogen atom or an oxygen atom. Each of the bonds between C.sub.11 and P.sub.4, C.sub.11 and P.sub.3, P.sub.4 and P.sub.3, P.sub.3 and P.sub.2, P.sub.2 and P.sub.1, and P.sub.1 and C.sub.10 is a single bond or double bond. L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; and M represents a transition metal element in Groups VIII to X of the periodic table.
In Formula (1), when Ra, Rb, Rc, Rd, Re, Rf, Rg, or R.sub.0 represents a substituent, the examples of the substituent include alkyl groups such as methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, and pentadecyl groups; cycloalkyl groups such as cyclopentyl and cyclohexyl groups; alkenyl groups such as vinyl and allyl groups; alkynyl groups such as ethynyl and propargyl groups); aromatic hydrocarbon ring groups also referred as aromatic hydrocarbon groups, aromatic carbocyclic groups or aryl groups such as phenyl, p-chlorophenyl, mesityl, tolyl, xylyl, naphthyl, anthryl, azulenyl, acenaphthenyl, fluorenyl, phenanthryl, indenyl, pyrenyl, and biphenylyl groups; aromatic heterocyclic groups such as pyridyl, pyrimidinyl, furyl, pyrrolyl, imidazoiyl, benzimidazolyl, pyrazolyl, pyrazinyl, triazolyl (for example, 1,2,4-triazol-1-yl and 1,2,3-triazole-1-yl), oxazolyl, benzoxazolyl, thiazolyl, isoxazolyl, isothiazolyl, furazanyl, thienyl, quinolyl, benzofuryl, dibenzofuryl, benzothienyl, dibenzothienyl, indolyl, carbazolyl, carbolinyl, diazacarbazolyl (a group in which one of the carbon atoms in the carboline ring in the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl, pyridazinyl, triazinyl, quinazolinyl, and phthalazinyl groups; heterocyclic groups such as pyrrolidyl, imidazolidyl, morpholyl, and oxazolidyl groups; alkoxy groups such as methoxy, ethoxy, propyloxy, pentyloxy, hexyloxy, octyloxy, and dodecyloxy groups; cycloalkoxy groups such as cyclopentyloxy and cyclohexyloxy groups; aryloxy groups such as phenoxy and naphthyloxy groups; alkylthio groups, such as methylthio, ethylthio, propylthio, pentylthio, hexylthio, octylthio, and dodecylthio group; cycloalkylthio groups such as cyclopentylthio and cyclohexylthio groups; arylthio groups such as phenylthio and naphthylthio groups; alkoxycarbonyl groups such as methyloxycarbonyl, ethyloxycarbonyl, butyloxycarbonyl, octyloxycarbonyl, and dodecyloxycarbonyl groups; aryloxycarbonyl groups such as phenyloxycarbonyl and naphthyloxycarbonyl groups; sulfamoyl groups such as aminosulfonyl, methylaminosulfonyl, dimethylaminosulfonyl, butylaminosulfonyl, hexylaminosulfonyl, cyclohexylaminosulfonyl, octylaminosulfonyl, dodecylaminosulfonyl, phenylaminosulfonyl, naphthylaminosulfonyl, and 2-pyridylaminosulfonyl groups; acyl groups such as acetyl, ethylcarbonyl, propylcarbonyl, pentylcarbonyl, cyclohexylcarbonyl, octylcarbonyl, 2-ethylhexylcarbonyl, dodecylcarbonyl, phenylcarbonyl, naphthylcarbonyl, and pyridylcarbonyl groups; acyloxy groups such as acetyloxy, ethylcarbonyloxy, butylcarbonyloxy, octylcarbonyloxy, dodecylcarbonyloxy, and phenylcarbonyloxy groups; amido groups such as methylcarbonylamino, ethylcarbonylamino, dimethylcarbonylamino, propylcarbonylamino, pentylcarbonylamino, cyclohexylcarbonylamino, 2-ethylhexylcarbonylamino, octylcarbonylamino, dodecylcarbonylamino, phenylcarbonylamino, and naphthylcarbonylamino groups; carbamoyl groups such as aminocarbonyl, methylaminocarbonyl, dimethylaminocarbonyl, propylaminocarbonyl, pentylaminocarbonyl, cyclohexylaminocarbonyl, octylaminocarbonyl, 2-ethylhexylaminocarbonyl, dodecylaminocarbonyl, phenylaminocarbonyl, naphthylaminocarbonyl, and 2-pyridylaminocarbonyl groups; ureido groups such as methylureido, ethylureido, pentylureido, cyclohexylureido, octylureido, dodecylureido, phenylureidonaphthylureido, and 2-pyridylaminoureido groups; sulfinyl groups such as methylsulfinyl, ethylsulfinyl, butylsulfinyl, cyclohexylsulfinyl, 2-ethylhexylsulfinyl, dodecylsulfinyl, phenylsulfinyl, naphthylsulfinyl, and 2-pyridylsulfinyl groups; alkylsulfonyl groups such, as methylsulfonyl, ethylsulfonyl, butylsulfonyl, cyclohexylsulfonyl, 2-ethylhexylsulfonyl, and dodecylsulfonyl groups; arylsulfonyl groups or heteroarylsulfonyl groups, such as phenylsulfonyl, naphthylsulfonyl, and 2-pyridylsulfonyl groups; amino groups such as amino, ethylamino, dimethylamino, diphenylamino, butylamino, cyclopentylamino, 2-ethylhexylamino, dodecylamino, anilino, naphthylamino, and 2-pyridylamino groups; halogen atoms such as fluorine, chlorine and bromine atoms; fluorohydrocarbon groups such as fluoromethyl, trifluoromethyl, pentafluoroethyl, and pentafluorophenyl groups; cyano groups, nitro groups, hydroxy groups, mercapto groups, silyl groups such as trimethylsilyl, triisopropylsilyl, triphenylsilyl, and phenyldiethylsilyl groups; and phosphono groups. Preferred are alkyl groups, aromatic hydrocarbon ring groups, aromatic heterocyclic groups, and alkoxy groups.
Moreover, these substituents may be further substituted with above-described substituents.
Preferred examples of the further substituent on the substituents Ra, Rb, Rc, Rd, Re, Rf, Rg, and R.sub.0 in Formula
include alkyl groups, aromatic hydrocarbon ring groups, aromatic heterocyclic groups, alkoxy groups, and amino groups.
In Formula (1), A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. Examples of the aromatic hydrocarbon ring group include phenyl, p-chlorophenyl, mesityl, tolyl, xylyl, naphthyl, anthryl, azulenyl, acenaphthenyl, fluorenyl, phenanthryl, indenyl, pyrenyl, and biphenylyl groups. Examples of the aromatic heterocyclic group include pyridyl, pyrimidinyl, furyl, pyrrolyl, imidazoiyl, benzimidazolyl, pyrazolyl, pyrazinyl, triazolyl (for example, 1,2,4-triazole-1-yl and 1,2,3-triazole-1-yl groups), oxazolyl, benzoxazolyl, thiazolyl, isoxazolyl, isothiazolyl, furazanyl, thienyl, quinolyl, benzofuryl, dibenzofuryl, benzothienyl, dibenzothienyl, indolyl, carbazolyl, carbolinyl, diazacarbazolyl (a group in which one of the carbon atoms in the carboline ring in the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl, pyridazinyl, triazinyl, quinazolinyl, and phthalazinyl groups).
A.sub.0 preferably has a substituent, and preferred examples of the substituent include alkyl groups, aromatic hydrocarbon ring groups, aromatic heterocyclic groups and alkoxy groups. Preferred are aromatic hydrocarbon ring groups.
In Formula (2), A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa, and Ra represents a hydrogen atom or a substituent, D.sub.1, D.sub.2, and D.sub.3 each represent CRb or a nitrogen atom, and Rb represents a hydrogen atom or a substituent, A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom. X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand, and X.sub.1 and X.sub.2 each independently represents a carbon atom, a nitrogen atom or an oxygen atom, L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2. And M represents a transition metal element in Groups VIII to X of the periodic table.
In Formula (2), when Ra, Rb, or R.sub.0 represents a substituent, it has the same meaning as Ra, Rb, or R.sub.0 in Formula (1); and a plurality of Rb do not form, any ring by mutual bounding.
In Formula (2), when A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group, it has the same meaning as A.sub.0 in Formula (1).
In Formula (3), A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa, and Ra represents a hydrogen atom or a substituent. R.sub.61, R.sub.62 and R.sub.63 each represent a hydrogen atom or a substituent. A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group; B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom. X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand, and X.sub.1 and X.sub.2 each independently represents a carbon atom, a nitrogen atom or an oxygen atom; and L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2. And M represents a transition metal element in Groups VIII to X of the periodic table.
In Formula (3), when Ra, R.sub.61, R.sub.62, R.sub.63, or R.sub.0 represents a substituent, it has the same meaning as Ra, Rb, Rc, Rd, or R.sub.0 in Formula (1).
In Formula (3), when A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group, it has the same meaning as A.sub.0 in Formula (1).
In Formula (4), A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa, and Ra represents a hydrogen atom or a substituent. Z.sub.0 represents an oxygen atom or a sulfur atom. Z.sub.1, Z.sub.2, and Z.sub.3 each represent C(RcRd), NRe, Si(RfRg), an oxygen atom or a sulfur atom; and Rc, Rd, Re, Rf, and Rg each represent a hydrogen atom or a substituent. A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or si sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom, X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand, and X.sub.1 and X.sub.2 each independently represents a carbon atom, a nitrogen atom or an oxygen atom; and L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2. M represents a transition metal element in Groups VIII to X of the periodic table; and R.sub.61, R.sub.62 and R.sub.63 do not form any ring by mutual bounding.
In Formula (4), when Ra, Rc, Rd, Re, Rf, or Rg represents a substituent, it has the same meaning as Ra, Rb, Rc, Rd, or R.sub.0 in Formula (1).
In Formula (4), when A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group, it has the same meaning as A.sub.0 in Formula (1); and Rc, Rd, and Re do not form any ring by mutual bounding.
In Formula (5), A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa, and Ra represents a hydrogen atom or a substituent, Y.sub.1 represents an oxygen atom, a sulfur atom, C(RcRd), NRe or Si(RfRg); and Rc, Rd, Re, Rf, and Rg each represent a hydrogen atom or a substituent, R.sub.71 represents a hydrogen atom or a substituent; A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group; B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom. X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand, and X.sub.1 and X.sub.2 each independently represents a carbon atom, a nitrogen atom or an oxygen atom; and L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2. M represents a transition metal element in Groups VIII to X of the periodic table.
In Formula (5), when Ra, Rc, Rd, Re, Rf, or Rg represents a substituent, it has the same meaning as Ra, Rb, Rc, Rd, or R.sub.0 in Formula (1).
In Formula (5), when A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group, it has the same meaning as A.sub.0 in Formula (1); and R.sub.71, Rc, and Rd do not form any ring by mutual bounding.
In Formula (6), A.sub.1 and A.sub.2 each represent a nitrogen atom, or CRa, and Ra represents a hydrogen atom or a substituent, Y.sub.2 represents a nitrogen atom or CRb, and Rb represents a hydrogen atom or a substituent. Y.sub.3 represents an oxygen atom or a sulfur atom; R.sub.81 represents a hydrogen atom or a substituent; and A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group.
B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom, X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand, and X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom; L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; and M represents a transition metal element in Groups VIII to X of the periodic table.
In Formula (6), when Ra, Rb, or R.sub.81 represents a substituent, it has the same meaning as Ra, Rb, Rc, Rd, or R.sub.0 in Formula (1); and R.sub.81 and Rb do not form any ring by mutual bounding.
In Formula (6), when A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group, it has the same meaning as A.sub.0 in Formula (1).
In Formula (7), A.sub.1 and A.sub.2 each represent a nitrogen atom or CRa, and Ra represents a hydrogen atom or a substituents Y.sub.4 represents an oxygen atom or a sulfur atom; and Y.sub.5 and Y.sub.6 each represent C(RcRd), NRe, Si(RfRg), an oxygen atom or a sulfur atom, Rc, Rd, Re, Rf, and Rg each represent a hydrogen atom or a substituent; A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group; and B.sub.1 to B.sub.5 each represent a carbon atom, CR.sub.0, a nitrogen atom, an oxygen atom or a sulfur atom, provided that at least one of B.sub.1 to B.sub.5 represents a nitrogen atom.
X.sub.1-L.sub.1-X.sub.2 represents a bidentate ligand, and X.sub.1 and X.sub.2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L.sub.1 represents an atomic group that forms a bidentate ligand with X.sub.1 and X.sub.2; and M represents a transition metal element in Groups VIII to X of the periodic table.
In Formula (7), when Ra, Rc, Rd, Re, Rf, or Rg represents a substituent, it has the same meaning as Ra, Rb, Rc, Rd, and R.sub.0 in Formula (1). Rc, Rd, and Re do not form any ring by mutual bounding.
In Formula (7), when A.sub.0 represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group, it has the same meaning as A.sub.0 in Formula (1).
Compounds represented by Formulae
to
can preferably be used among other compounds represented by Formula (1).
In the present invention, preferred are compounds represented by Formulae
to (7), and most preferred are compounds represented by Formulae
and (7).
In Formulae
to (7), n represents an integer of 1 to 3; and m represents an integer of (3-n). In the present invention, a preferred case is n=3 and m=0.
In Formulae
to (7), a ring formed by B.sub.1 to B.sub.5 is preferably an imidazole ring or a pyrazole ring, and most preferably an imidazole ring.
M represents a transition metal element in Groups VIII to X of the periodic table, and preferred is iridium.
Specific examples of a bidentate ligand represented by X.sub.1-L.sub.1-X.sub.2 in the structure represented by any one of Formulae
to
according to the present invention include substituted or unsubstituted phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabole, acetylacetone, and picolinic acid.
The compound A may be exemplified below, but not limited to:
##STR00009## ##STR00010## ##STR00011## ##STR00012## ##STR00013## ##STR00014## ##STR00015## ##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025## ##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033## ##STR00034##
Preparation of the compounds represented by Formula
will be described referring to preparations of the compounds represented by Formulae
to
which are specific compounds for compounds represented by Formula
by way of example.
(Preparation of Exemplary Compound 1)
An exemplary compound 1 (corresponding to Formula (7)) was prepared by the following process.
(Preparation of μ-Complex)
The description continues in the full USPTO document.
About 6,085 words. The USPTO PDF has it with every drawing.
Fees are due 3.5, 7.5 and 11.5 years after grant. This patent expired on March 20, 2026, so the fee marked "not paid" was the one that went unpaid.
ORGANIC ELECTROLUMINESCENT ELEMENT, LIGHTING DEVICE, AND DISPLAY DEVICE
Filed Feb 2012 · published Dec 2013Organic electroluminescent element, lighting device, and display device
Filed Feb 2012 · granted Mar 2018Earlier publications, parents and continuations. None of them can still be enforced, or this patent would not be listed.
Prior art cited by the examiner or applicant. Useful when you check your own idea for novelty.
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